The invention relates to methods and apparatus for processing documents of value such as banknotes, cheques, postal orders and the like.
The need for rapid counting of paper sheets, for example documents of value such as banknotes, has been long established and the introduction of the single pocket note counter provided major improvements in efficiency. These products were however somewhat limited as they could only count the number of pieces of paper that were conveyed through the machine regardless of their value or authenticity.
Over the course of time further developments added size detection as a means of detecting rogue notes within a bundle of currency and indeed the further application of the size measurements allowed a determination of the value of the currency to be obtained. Providing of course that each denomination was of a discernibly different size. The processing by value of currency whose notes were all the same size, for example the US Dollar, was achieved by the step of using a pattern detector instead of a size detector.
Similarly, the development of authentication devices allowed potential counterfeit notes to be identified during the note processing operation. Because of the need for these devices to be generic to all currencies only the simplest forms of authentication, such as UV fluorescence, were originally applied. Later currency specific devices for widely circulated currencies such as the US Dollar were developed. This latter authentication was almost invariably some form of magnetics detection. Detecting magnetic features is limiting, as the note needs to form intimate contact with the sensing head, which places arduous demands on the transporting of the banknotes. This can be particularly limiting when processing limp or damaged currency.
The problem with the addition of this increased sophistication was that invariably the achievable note throughput would fall. This was because each time a problem note was identified the product would have to stop to allow the operator to examine ad process the identified note. This was overcome by the introduction of counting devices that had more than one pocket and could therefore operate in a continuous manner (like a note sorter) whereby the problem note could be off sorted to either a second pocket or a reject area. The operator could now process the problem notes without the machine needing to stop thus greatly enhancing the efficiency of the product. Similar problems have been experienced in equipment for accepting cash deposits where there has become a requirement for more rapid accurate recognition and authentication of deposited documents as the time to process the acceptance or otherwise of inserted individual or bundles of documents is reduced.
As stated earlier the types of authentication applied to such products have been chosen to be of a generic type applicable to most currencies or specifically targeted at the US Dollar. Detection techniques such as UV are now often regarded as of little benefit against the types of forgeries that are being created.
In accordance with one aspect of the present invention, a method of processing documents of value comprises:
a) detecting a visible pattern on at least one side of a document;
b) detecting the response of at least one side of the document to infrared radiation;
c) comparing the detected visible pattern to one or more predetermined patterns and identifying the document if the detected visible pattern is sufficiently similar to the or one of the predetermined patterns; and,
d) determining from the response to infrared radiation it the document is authentic.
In accordance with another aspect of the present invention, apparatus for processing documents of value comprises a visible pattern detection system for detecting a visible pattern on at least one side of a document; an infrared response detection system including at least one infrared detector and infrared emitter for detecting the response of at least one side of a document to infrared radiation; and a processor for comparing the detected visible pattern to one or more predetermined patterns so as to identify the document if the detected visible pattern is sufficiently similar to the or one of the predetermined patterns, and for determining from the response to infrared radiation it the document is authentic.
The invention enables a new form of non-contact detection to be introduced into the banknote counting product environment that provides enhanced authentication processing that was previously only found in the much higher cost banknote sorting arena. The non-contact nature of the detector providing the advantage that note guiding constraints are minimised and the range of notes that can be processed is maximised.
Commonly available equipment such as PC""s with scanners and inkjet printers are now capable of creating visual images that are difficult to discern as being a counterfeit and matching the UV characteristics of a banknote is easily achieved. However, it is known that the inks used to create these images do nor result in any form of image being visible when the note is illuminated and viewed in the IR spectrum. Real bank notes may be printed with inks that are known to produce a controlled response in the IR spectrum, albeit the response produced under IR light does not necessarily bear any relation to that in the visible domain. Indeed some banknotes are produced with inks, such as the De La Rue Delacode type, that are colour matched in the visible spectrum but that respond differently in the IR. A note can thus be printed with a continuous colour block in the visible and a varying intensity level in the IR.
Processing such notes is best carried out in both the visible and IR spectra with the IR response being examined separately for each side of the note. The visible image is checked to ensure that it conforms to the visual aspects of the note and the IR spectra is checked for its authenticity. The IR response should be particularly checked in areas that are known to be printed with the colour matched types of ink.
In one application, the method is used in a two pocket value balancing counter that is capable of providing a variety of functions inclusive of continuous note processing whilst simultaneously determining the value and authenticity of each note. A transmissive visible pattern detector determines the value of the note. The product is considerably enhanced by the addition of an IR detector that can operate in conjunction with the pattern detector.